Files requiring PCMachineClass already include "hw/i386/pc.h".
To clean "qemu/typedefs.h", move the declaration to "hw/i386/pc.h"
(removing the forward declaration).
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>